* {
    margin: 0;
    padding: 0;
}

body {
    background: #23ff29;
}

p {
    text-align: center;
    font-size: 24px;
    font-weight: bold;
    color: white;
}

.outer {
    position: relative;
    width: 500px;
    height: 500px;
    background: #222222;
    margin: 20px auto;
}

.green {
    position: absolute;
    left: 2px;
    top: 2px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: green;
}